Vision System Calibration with Ball Bars (Dumbbells, VDI/VDE)

Technical Information

There are two schools of thought on balls for vision systems. The first is aluminum oxide ceramic, which works well and isn't expensive in small diameters, 1.00 inch ( 25.4 mm ). The price goes out of sight for anything over 2.00 inches ( 50 mm ) diameter. Satin finished titanium is being widely used in some circles, and doesn't get too expensive until you get over 4.00 inches ( 100 mm ) diameter.

The dumbbells are manufactured to nominal lengths. When balls of different sizes are put on each end of the dumbbell, serious metrology problems are generated. Determining the axis and compensating for elastic deformation is nearly impossible. Our calibration uncertainty is limited to + or - three microns. N.I.S.T., P.T.B. or N.P.L. can give sub parts per million calibration. Our standard one inch diameter satin finished ceramic balls on an Invar bar costs $426.00.

N.I.S.T. traceable calibration is $146.00. Normal delivery is four weeks. Our standard two inch diameter satin finished ceramic balls on an Invar bar are $1,446.00. N.I.S.T. traceable calibration is $146.00. The bars are black satin finished. We offer the standard, satin finished, titanium straight edge that is one and one half inches ( 38.1 mm ) wide by eight inches ( 203.2 mm ) long at $486.00. The flatness tolerance is one micrometer. Estimated delivery is three weeks. We can quote any length and width up to 34 inches ( 863.6 mm ) long on a custom basis. CMM Products Directory